CFR›Title 21›Chapter I›Part 338 ContainsSubparts A–CCorpusDaily eCFRDisplayed edition2026-04-15Last updated2026-04-15 PART 338—NIGHTTIME SLEEP-AID DRUG PRODUCTS FOR OVER-THE-COUNTER HUMAN USE Subparts A Subpart A—General Provisions Sections 338.1–338.3 B Subpart B—Active Ingredients Section 338.10 C Subpart C—Labeling Section 338.50 Authority21 U.S.C. 321, 351, 352, 353, 355, 360, 371.Source54 FR 6826, Feb. 14, 1989, unless otherwise noted. Previous 336 Part 336—Antiemetic Drug Products for Over-the-Counter Human Use Next 340 Part 340—Stimulant Drug Products for Over-the-Counter Human Use